There’s no getting away from it – Celtic’s 7-1 defeat to Borussia Dortmund in the Champions League stings. There was so much optimism going into the match. Nine wins from nine, a towering European performance on the opening night, and significant confidence projected by Brendan Rodgers and his players. It promised to be a bright new dawn for Celtic in Europe. Nobody expected victory, but many thought that the Scottish champions could be competitive against last year’s tournament finalists. In the end, that was a naive hope. Dortmund repeatedly punished Celtic mistakes and dismantled the Bhoys’…